Instructor Talk and Student Belonging in Introductory Biology: Not all Talk Matters and Relationships Vary by Student Identity.

What instructors say during class-beyond content-has promise for supporting students' perceptions that they are supported, connected, and valued in the classroom, which in turn predict positive outcomes in science, technology, engineering, and mathematics (STEM) education. We studied noncontent Instructor Talk used by 56 introductory biology instructors around the United States and how it related to sense of belonging among over 4900 students in their courses. Using hierarchical linear modeling, we identified positive relationships between some-but not all-categories of Instructor Talk and belonging among students. Instructor talk aimed at building relationships with students and explaining pedagogical choices had positive relationships with students' sense of connectedness to peers (for both) and comfort seeking instructor help (for the former), but not their comfort sharing ideas with the class. Using effect coding, we probed whether these relationships differed for students with 14 intersectional identities, including men and women from seven racial and ethnic groups. Relationships between Instructor Talk categories and components of belonging varied in their direction and magnitude for students with different intersectional identities. Findings demonstrate that even simple instructor actions-particularly language-may be meaningful to students, but we cannot assume that all students experience these actions the same way.